John Sonnier

William Blair & Company

Managing Director

John Sonnier is Managing Director at William Blair & Company, where he leads its biopharma investment banking practice. Mr. Sonnier was formerly an equity research analyst at William Blair. He joined William Blair in 2005 to build the firm’s biopharma equity research practice. Before coming to William Blair, Mr. Sonnier was a biotechnology equity research analyst for seven years with the Prudential Equity Group; previously, he spent eight years in various commercial and strategic roles at Johnson & Johnson and Baxter International. Mr. Sonnier has a BS from University of Southern Mississippi and a Master of Public Health degree from Johns Hopkins University.